score = input("请输入一个分数：")
if score.isdigit():
    score = int(score)
    if(score > 100):
        print("您输入的数据有误:", score)
    elif(100 >= score and score >= 90):
        print("A")
    elif(90 > score and score >= 80):
        print("B")
    elif(80 > score and score >= 70):
        print("C")
    elif(60 > score and score >= 0):
        print("D")
    else :
        print("您输入的数据有误:", score)
else :
    print("您输入的数据有误:", score)
